Our implementation of the LRA specification exposes REST endpoints whose semantics may change over time. As the LRA spec evolves users will need a guarantee that the endpoints behave consistently.

To avoid introducing breaking changes I propose that we version REST API calls made by the implementation using a version header, something like:

OpenStack-API-Version: narayana LRA 5.10.5.Final

or

OpenStack-API-Version: narayana LRA 5.10.5.Final https://<the location of our OpenAPI document>

I went for the OpenStack guideline since it was the only standard I could find for custom headers.

A reason it is narayana specific is that our API offers more than the spec requires.